INTERJET ENERGY FLOW in photoproduction dijet events with large rapidity gaps
{"Image DocumentName": "INTERJET ENERGY FLOW in photoproduction dijet events with large rapidity gaps", "Image ImageDescription": "Idea. Normally lots of activity between two jets \uf0e0 color connection. Events with little activity between jets: study color singlet exchange in pQCD regime (high ET!) pomeron. gap. Compare. to MC models with(out) color singlet (CS) contribution: -- PYTHIA: high-t-\uf067 exchange (MPI); -- Herwig: BFKL-Pomeron (JIMMY) added to dir+res. Dijets in photoproduction events from 96/97. What is this useful for? Might help for better understanding of diffractive and underlying event. Study as function of amount of energy between jets Etgap. Selection: Photoproduction dijets with 6/5 GeV, |eta|<2.4 and large rap separation of jets between 2.5 and 4 units in rapidity. 38pb-1 von 96/ <y<0.85. Normal MC: Problems if very little or no energy Etgap! \uf0e0 Try other models with CS contribution: PYTHIA high-t-gamma exchange (fake), HERWIG with BFKL-Pomeron. Necessary CS contribution 3-4% total distributions. If we increase CS contribution by requiring Etgap < Etcut=1 GeV \uf0e0 20-50% CS needed \u2013 depending on separation of jets \u2013 the farther apart the higher the CS contribution necessary to describe the data. As function of rapidity separation normal predictions fall exponentially \u2013 as you would expect since it becomes more and more improbable to NOT radiate anything the farther the two jets are apart. But data and CS models level out! Fall=-off only seen in data and CS MC at low ETCUt. Result. Globally 3-4% CS exchange needed to account for small Etgap cross- section. Amount depends on rapidity separation of jets (up to 50%). Bonn, 11. Mai TSS: QCD bei HERA.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}